Cam-actuated door support and clamp



.1 Nov. 25, 1952 HARTWELL 2,619,137

CAM-ACTUATED DOOR SUPPORT AND CLAMP Filed Oct. 21, 1947 lllllllllllllll liilllliilllfliilifiiilliflllIlllllllllilllllllllllllllllli INVENTOR. ROBERT M HARTWELL ATTX Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE CAM-ACTUATED DOOR SUPPORT AND CLAM 3 Claims.

This invention relates to clamps and more particularly to a portable clamp for supporting a flat structural member, such as a door or a sash, in a position which will be convenient to a carpenter Working upon said member.

In the installation of doors, it is customary to fit the doors at the locations where they are to be installed. The fitting operation entails considerable work upon the edge surfaces of each door before it is hung in place, such as planing and mortising, and unless special provision is made to support the door firmly in a vertical plane, this work cannot be performed efiiciently. Heretofore, the provision of an eflicient support for this purpose has been neglected because of the necessity that the support be easily portable, and carpenters have been compelled either to work upon the door at a distance from the site of installation, or to resort to makeshift arrangements.

Accordingly, one object of this invention is to provide a device of the above nature which includes means for clamping and supporting a door firmly in a vertical position.

Another object is to provide a device of the above nature which is easily portable.

Another object is to provide a device of the above nature in which the clamping device is automatically adjustable to varying thicknesses of doors.

Another object is to provide a device of the above nature which may be readily assembled from standard stock materials by means of welding.

A further object is to provide a device of the above nature which will be simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, ornamental in appearance, and very eificient and durable in use.

With these and other objects in view, there has been illustrated on the accompanying drawing one form in which the invention may conveniently be embodied in practice.

In the drawings,

Fig. 1 is a perspective View of the improved door clamp and a door engaged therein, partly broken away.

Fig. 2 is a fragmentary plan view thereof on an enlarged scale, showing features of the clamping device.

Fig. 3 is a perspective view as seen from the left of Fig. 2.

Fig. 4 is a sectional view showing the connection of the stabilizing member to the base.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral I indicates a support of inverted T-shape comprising an elongated base member II having a vertical standard I2 secured to its central portion. The base member II and the standard I2 are formed of lengths of angle iron which are welded together in such a relation that the rear flange I3 of the standard I2 laps the erect rear flange I 4 of the base member I I, and the forward flange I5 of the standard I2 abuts the bottom flange I6 of the base member I I.

An elongated stabilizing arm I1 is welded in abutting relation to the front edge of the bottom flange I6 of the base member adjacent to the standard I2. The stabilizing arm I! and the base member II preferably are provided with apertures I8, I9, respectively, whereby the door clamp may be firmly secured to the floor by means of nails or screws. If desired, the efi'ective length of the arm I! may be extended by means of an elongated member Ila which may be secured by nails or screws through the apertures I8 and apertures I9a in the flange I6.

In order to clamp a door D firmly against the side of the standard I2, a clamping device 20 is mounted adjacent the upper end of said standard. The clamping device 20 includes a rectangular clamp bar 2| slidably held in a horizontal position against the rear face of the standard I2 by a U-shaped strap 22 welded to said standard. A clamp screw 23 having a handle 24 is threaded into the strap 22 whereby the clamp bar 2| may be firmly gripped. The clamping device 20 further includes a movable jaw 25 in the form of a flat plate which is provided adjacent one end with a rectangular aperture 25 embracing the clamp bar 2| whereby the jaw 25 is slidably mounted. A guide rod 21 is welded to the rear face of the jaw 25 in parallel relation to the clamp bar 2|, and is slidably supported in a bracket 28 welded at right angles to the end of the clamp bar 2 I.

The movable jaw 25 is normally held in a retracted position by a coil spring 29 embracing the end portion of the guide rod 21 outwardly of the bracket 28 and retained thereon by a washer 30 and a cotter pin 3|. In order to move the jaw 25 toward the standard I2 and into clamping engagement with the door D, provision is made of a pair of coacting tubular cam pieces 32, 33 embracing the guide rod 21 inwardly of the bracket 28. These cam pieces preferably are formed of pipe so cut as to have coacting inclined cam surfaces 34, 35, respectively, and then casehardened. The cam piece 32 is welded to the inner surface of the .bracket 28, while the cam piece 33 abuts a washer 36 adapted to act through a coil spring 31 embracing the guide rod 21 to urge the jaw 25 to its clamping position. The spring 31 is relatively stiff as compared with the spring 29.

The cam piece 33 is provided with a radial handle 38 welded thereto in such a position that said handle will contact the lower corner of the clamp bar 2I when the high point of the inclined cam surface 35 of the cam piece 33 has just passed the high point of the cam surface 34 of the cam piece 32.

A fixed jaw piece 39 is welded in coplanar abutting relation to the forward flange I of the standard I2 opposite the movable jaw whereby the flange I5 and said jaw piece 39 will serve as a fixed jaw adapted to cooperate with the movable jaw 25 in clamping the door D.

Operation In operation, the improved carpenters door clamp will be carried to the location where it is to be used, which will preferably be in the vicinity of the door frame in which the door is to be hung. Although the clamp will be sufficiently stable without any special securement, it will sometimes be found preferable to nail the clamp to the floor through the apertures I8, I9 which are provided. If the work is being done in a new building, the clamp may be readily nailed to the sub flooring without causing any material damage. However, if it is desired to improve the stability of the clamp without fixing it in one place, an elongated member such as a piece of scrap lumber IIa may be secured to the upper surface of the arm I1 and the flange I6 by means of screws or nails engaged through the apertures I8 and ISa.

The handle 38 will be turned upwardly so that the spring 29 will move the jaw 25 away from the standard I2, and the end of the door D will then be insertedbetween the standard I2 and the jaw 25.

At this point, the movable jaw 25, the cam piece 33, the washer 36, and the handle 38 will occupy the positions 25', 33', 36' and 38', respectively, as shown in Fig. 2.

The lower corner of the door will be supported in the seat which is formed by the intersection of the base member II and the standard I2, or upon the piece IIa if this piece is used. These members will serve to locate the lower edge of the door accurately, and the stabilizing arm I'I will underlie the door so as to aid in holding the apparatus in position.

In order for the clamp to work properly, the movable jaw 25 when in its open position should be spaced from the standard I2 by a distance somewhat greater than the thickness of the door D. This open position of the jaw 25 may be adjusted to suit the operator by loosening the clamp screw 23 so that the clamp bar 21 may be slid in the U-shaped strap 22 to the desired position, whereupon the screw 23 will be tightened. This adjustment of the-clamp bar 2I will not ordinarily need to be disturbed unless a door of substantially different thickness is to: be worked upon.

When the clamp bar 2I is secured firmly in the desired position, the handle 38 will be swung downwardly so as to rotate the cam piece 33, whereupon the cam face will be forced to the right by the cam face 34 until the high points of the cam pieces just pass each other, into the position shown by the full lines in Fig. 2. In this position the handle 38 will lie in contact with the lower corner of the clamp bar 2|, thereby preventing further movement of the cam piece 33.

It will be noted that as the cam piece 33 rotates, it will move gradually toward the standard I2.

Inasmuch as the coiled spring 31 is stiffer than the spring 29, the spring 31 will not yield during the first part of the clamping operation whereby the movable jaw 25 will be forced toward the door D against the pressure of the spring 23. After the jaw 25 comes into contact with the surface of the door, no further movement of the jaw 25 will occur, and the continued movement of the cam piece 33 will result merely in compression of the spring 31. It will be seen that this arrangement will permit doors of different thicknesses to be clamped efiiciently, without requiring any special adjustment of the door clamp. Further, the force exerted upon the door by the jaw 25 will be limited by the resiliency of the spring 31, so that excessive forces which might mar the door finish will be avoided.

The door will then be firmly held in a vertical plane with its edge surface presented upwardly so that any desired operations such as planing, mortising, or the application of Weatherstripping may be performed thereon. When the work is finished, the door may be quickly and easily released from the clamp, merely by swinging the handle 38 upwardly, whereupon the spring 29 will retract the jaw 25 to free it from the door.

One advantage of the improved door clamp herein disclosed is that it is easily portable and may be used in substantially any location where the carpenter may wish to work. Thus, the clamp may not only be used at various locations within a building, but may be used in the planing of storm sashes, etc. wherein it will be advantageous to use the clamp at various locations out of doors.

Another advantage is that the clamp will operate efliciently With doors of somewhat different thicknesses without requiring adjustment of the clamp bar. However, if it should become necessary to clamp a door of unusual thickness, adjustment of the clamp bar 21 will be a simple matter.

It will be understood that the door clamp will be useful for holding objects other than doors, such as screen frames, window sashes, and other types of panels.

While there has been disclosed in this specification one form in which the. invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure, but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. In a carpenters door clamping apparatus, an elongated base member, a standard secured to said member, and a device secured to the upper end portion of said standard for clamping a door against the side of said standard, said clamping device comprising a horizontal clamp bar secured to said standard, a jaw slidably mounted thereon in opposed relation to the side of said standard, and cam mechanism for moving saidjaw toward said standard, including a cam piece rigidly secured to said clamp bar, a movablev cam piece engaged with said rigid cam piece, a'firstresilient means for applying the force of said cam mechanism to said jaw, whereby excessive clamping pressure upon a door will be avoided and a second resilient means for normally holding said jaw away from said standard.

2. The invention as defined in claim 1, including means for horizontal adjustment of said clamp bar upon said standard.

3. In a carpenters door clamping device, a standard, a horizontal bar attached to the top of said standard, said bar supporting a pair of door clamping jaws, one of which is rigidly secured to said bar, and the other jaw being movably mounted on said bar, a bracket rigidly secured to said bar, a rod rigidly secured to said movable jaw and slidable in said bracket parallel to said bar for guiding said movable jaw in its sliding movement, means for urging said movable jaw towards said rigid jaw including a pair of coacting truncated tubular cam pieces located on said rod, one of said cam pieces being rigidly secured to said bracket, a spring on said rod between said movable jaw and said other cam piece, a handle for manually rotating said other cam piece, and so disposed as to permit the high point on one cam piece to pass the high point on the other cam piece before said handle engages said bar, whereby reverse rotation of said cam piece will be prevented.

ROBERT H. HARTWELL.

REFERENCES CITED The following references are of record in the file of this patent: 

